Do you have any theories as to why Premier League moneybags Leicester City, who were clearly interested enough in signing George Hirst to have made such a 'reasonable' offer only six months earlier, wouldn't have offered better terms than Belgian second tier side OH Leuven?

...yet.
Maybe you're right and this isn't a way to get him to Leicester City via the backdoor, though.
Maybe George Hirst really did fancy a move away from the Championship to the Belgian second tier.
Only time will tell, I suppose.

Because The Guardian have published an article about it, commenting on its wider implications for the game as a whole.
As the article says:
But there is a principle here as well and if Hirst does turn up at Leicester, whenever that may be, it will tell us a lot about the politics and relationships that exist in modern football, the vagaries of the feeder-club system and a loophole that should probably be closed.
Plus it could be your club that gets hurt next time.
This may be the case which starts the ball rolling in terms of getting that loophole closed and preventing other clubs falling prey to the same practice.

No, as Hirst has left the club. The rumours of constantly moving goalposts in terms of what he'd accept, who should be arranging a loan deal, whether Hirst would accept certain loan deals, whether he was willing to engage in meaningful dialogue with the club...are just that: rumours.
Chansiri has made some very worrying decisions which have been discussed at length in other threads, but for me this issue is much bigger than that: it's about a Premier League club using their foreign feeder club to circumvent the usual payment due to a lower league club who have developed a young player. If this is allowed to become common practice, then many lower league clubs will suffer, and it will be their academies - the sole route into the game for so many young players - which fall by the wayside as a result. What that will do for player development in this country, I shudder to think.

If they were determined to shaft us, what could any chairman have done to prevent it, though?
Sell Hirst for £2m = shafted.
Refuse to sell and have him leave via an obscure loophole which prevents us being paid compensation for his development = shafted.

Again, we don't know exactly what led to the decision to prevent Hirst playing. I've heard speculation, but it remains just that as far as I'm concerned.
Clearly negotiations weren't progressing as expected and it seems Hirst was already in contact with Leicester as he was aware of their bid for him within an hour of it happening. Beyond that, who knows what was really going on behind closed doors?
Either way, we've fallen prey to some pretty shady practice on Leicester City's part which, if allowed to continue by the powers that be, could spell the end for academy football at lower league clubs in the not-too-distant future.
Hopefully the loophole that's allowed us to be screwed out of the usual compensation is closed before this kind of thing becomes common practice.

I'm not sure how that precludes the possibility that Chansiri asked George Hirst to prove his worth, only to be rebuffed by the player and his advisors. It's hardly unheard of for players looking for a move to make things as awkward as possible at their current club in order to engineer a move.
The bit I found most revealing from the chairman's statement is this: "The fact that the notification that George would not be signing for SWFC came just over an hour after we had turned down an offer from a Premier League club for the permanent transfer of George’s registration. Of course, this made us wonder if there were talks taking place with regards to George’s future which we were not party to."
It's pretty clear that he had his head turned by Leicester and had been in discussions with them without Wednesday's permission.

What if Chansiri said "OK, prove to us you’re worth this £x k a week by breaking into the team and banging the goals. Then we will work to meet you halfway", only to be told that no matter what, Hirst wouldn't be signing the contract and would be joining Leicester City or their Belgian feeder club at the end of his current deal?